#include <iostream>
#include <cmath>


class Point
{
public:
    Point(int x, int y)
    {
        this->x = x;
        this->y = y;
    }

    friend class PointTools;
private:
    int x;
    int y;
};
class PointTools
{
public:
    static double Distance(const Point& p1, const Point& p2)
    {
        return sqrt(pow(p1.x - p2.x, 2) + pow(p1.y - p2.y, 2));
    }
    static double DistanceToZero(const Point& p1)
    {
        return sqrt(pow(p1.x, 2) + pow(p1.y, 2));
    }
};
int main()
{
    Point p1(1,1);
    Point p2(2,2);
    std::cout << PointTools::Distance(p1, p2) << std::endl;
    return 0;
}